1.2.1169. String Int Comparison

While PHP allows direct comparison of integer and strings, with some type conversion, the rules of conversion changed in PHP 8.0. This lead to a change in behavior for comparison.

In particular, strings that are equal to 0, or empty strings, have changed.

This doesn’t affect identity comparison, since the type is initially checked.

<?php
                        PHP 7   PHP 8
var_dump(0 == "0");          true    true
var_dump(0 == "0.0");        true    true
var_dump(0 == "foo");   false   false

var_dump(0 > '');       false   true
var_dump(0 < '');       false   false
var_dump(0 >= '');      true    true
var_dump(0 <= '');      true    false

?>

See also String to Number Comparison.

1.2.1169.1. Connex PHP features

• comparison

1.2.1169.1.1. Suggestions

• Force a conversion to integer before the comparison to make sure of the behavior.

1.2.1169.1.2. Specs

Short name	Php/StringIntComparison
Rulesets	All, Changed Behavior, CompatibilityPHP80
Exakat since	2.3.9
PHP Version	With PHP 8.0 and more recent
Severity	Minor
Time To Fix	Quick (30 mins)
Changed Behavior	PHP 8.0
Precision	Medium
Available in	Entreprise Edition, Exakat Cloud